Thermoelectric properties of copper chalcogenide alloys deposited via the solution-phase using a thiol–amine solvent mixture

Abstract

We use soluble precursors to deposit Cu2−xSeyS1−y and Ag-doped Cu2−xSeyS1−y thin films. We report the effects of Cu vacancies, Ag doping, and Se : S ratio on the thermoelectric properties at room temperature.

High-performance thermoelectric silver selenide thin films cation exchanged from a copper selenide template

“…48,49,53 To form a thin-lm NC template, we adopted a method developed by Webber et al which demonstrated that bulk copper chalcogenides such as Cu 2 Se, Cu 2 Te and Cu 2 S can be dissolved in a thiol-amine solution mixture and be cast as thin lms on substrates. 45,51,54,55 However, bulk Ag 2 Se powder fails to do so at ambient conditions (see ESI, Fig. S3 †).…”

Rapid Stoichiometry Control in Cu2Se Thin Films for Room-Temperature Power Factor Improvement

“…12 Recently, Webber et al developed a method to completely dissolve metal chalcogenides, including Cu 2 Se, into a thiol-amine solution. 49−51 This binary solvent combination has the advantage of being less dangerous than hydrazine, 12 and the deposition of metal chalcogenides using this technique yields closely packed, void-free thin films without the need for spark plasma sintering or hot pressing. 11 The close contact of each crystalline grain within the thin film should lead to improved electron transport and an improved power factor in TE devices.…”

“…9−11 Traditional refrigerants possessing potent greenhouse gases can be replaced with the implementation of TE solid state cooling technology. 12 In addition, the emergence of wearable microelectronics 13−18 creates inspiration for flexible TE power generation and cooling devices that can be integrated into clothing. 19,20 To gauge the efficiency of a TE material, the figure of merit, , and power factor, α 2 σ, are two commonly used performance indicators, where α is the Seebeck coefficient, σ is the electrical conductivity, κ is the total thermal conductivity from electron and phonon contributions, and T is the absolute temperature of the material.…”

“…At a system level, to alleviate the cost of manufacturing and to develop flexible TE devices, solution processing 12,27,28 offers the advantages of manufacturing at lower temperatures and pressures while reducing the amount of waste material. 12,21 With solution processing, flexible thin films of TE material can be fabricated at a low cost. 29 Significant advancements in the TE research community have been reported in the past few decades; however, the materials and manufacturing processes used are still either too expensive or wasteful.…”

“…11 The best materials demonstrating high ZT at room temperature (typically around 1) have historically included the use of rare or toxic elements in inorganic crystalline semiconductors, such as Bi 2 Te 3 and Sb 2 Te 3 , and fabricated using energy intensive techniques, including vacuum melting and spark plasma sintering (SPS). 12,30,31 To address these shortcomings, Cu 2 Se has been proposed as a relatively nontoxic and abundant alternative with theoretical predictions of a maximum bulk ZT around 1.16 at 305 K. 32−34 Numerous experimental results have demonstrated promising TE performance of Cu 2 Se, while operating at high temperature (>800 K) with a ZT of around 1.5. 19,35−40 However, these high ZT values are only obtained via expensive manufacturing practices.…”